1. Field of the Invention Equipped
The present invention relates generally to a spiral-patterned internal antenna having an open stub and a personal mobile terminal equipped with the same and, more particularly, to the pattern of an open stub.
2. Description of the Related Art
As wireless mobile communication technologies develop, many products, such as a wireless portable mobile communication terminal and a Personal Digital Assistant (PDA), have been introduced, and antennas are principal communication parts that determine the performance of such wireless communication products. External monopole or helical antennas are mainly used as antennas applied to existing wireless portable mobile communication terminals. However, the external antennas have many disadvantages in that their characteristics may be changed by users if the external antennas are not fixed, the external antennas restrict the designs of wireless portable mobile communication terminals and PDAs, and their appearances are not beautiful. The selection of internal antennas is necessary to resolve the disadvantages of the external antennas. However, wireless portable mobile communication terminals and PDAs have spatial limitations, the application of internal antennas thereto is difficult.
Existing internal antennas applied to wireless portable mobile communication terminals are mainly Planar Inverted F-Antennas, and ceramic chip antennas and PIFA type-antennas are used as antennas for wireless PDAs.
The above-described PIFA antennas have narrow bandwidth, so that the radiation efficiency thereof decreases due to reflection loss at an input terminal, and resonance characteristics are exhibited at ¼ wavelength, and, thus, they have a disadvantage in that the size thereof increases. The ceramic chip antennas applied to wireless PDAs are made of high-dielectric material, so that they have a disadvantage in that the radiation efficiency thereof decreases.